Earth drill bit head



Nov. 28, 1939. c, A, N 2,181,394

I EARTH DRILL BIT HEA Filed Aug. 6, 1938 INVENTOR 0/424 A-DEAN.

' M ATTORNEY PatentedNov. 28, 1939 UNITED STATES PATENT OFFICE Y 2,181,394 I .212: $5332.. Application Au ust 6, 1938, Serial No. 223,405

L This invention pertains to bits for earth-drilling, such as may be used to sink bore holes for oil wells; and; pertainsparticularly to a bit head in which parts may readily be interchanged,

though thexbit be down in a bore hole.

ited, to core bits. continuously or samples -.at' intervals. For ex-' ample, in rock formations a long core may be cut efllciently; while in soft earth structures, a shorter core sample may be requisite. It is desirable that the driller be ab e to insert various lengths of core tube as he 'em best to meet difie'rent conditions. core and insert a center bit in lieu of a core tube, or insert a new core tube, without interfering with drilling by the bit as a whole. These drills may operate at'great depths in the earth, perhaps as much as twomiles deep, so that their adaptability, dependability and simplicity are important.

Of this invention animportant object is to provide ,a drill bit head which is readily convertible from a core drill-to a center drill, or vice versa. A further object is to replace a core tube readily in a bit, as with a grapple; and

Core bits may take samples Or that he may remove ainner member with vertical play actuates looking means for a central core tube or a center drilling bit. In a preferred form, an annular, floating cutter carrier, fitted in a central recess V of. the bit head, contains a latch, to close when 5 This invention is applicable, though not limthe. carrier rests on bottom and to pull open when the bit head is lifted. More specifically, a central cutter carrier. splined to float between vertical limits within the bit head, is shaped to wedge or force a spherical latch into a seat against 10 to improve the ease and certainty of operating crumbling the core as the bit is rotated or is played up and. down in drilling. A further oh- I ject'is to provide simple lockingmeans for a ceny'et ,gee to float or swivel with a core to avoidv tact with the embodiment shown in the drawing, but is not limited thereto, inasmuch as various objects and advantages of this invention may be accomplished by'oth r than the specific forms shown.

Referring M e' particularly to the drawing, a bit head is shown comprising an outer, somewhat massive shell I, adapted to befastened to the usual string of drill pipe, This member I carries any selected number of rotatable cutters 2|. Centrallyewithin this shell is a substantial recess. Housed within this recess of the bit head is a columnar member 4. A central opening extends through this member to communicate .with the usual drill pipe for reception of a core barrel, of a center drill or other cylindrical element. In Fig. 1 is shown a core barrel 2, while in Fig. 3 is shown a center bit 8. The member 4 is adapted to reciprocate vertically with motion of the drill to lock and to unlock the core barrel or the center drill.

As shown, i er member 4 extends from con- 5 tom of the bore hole up into the bit head recess suillciently to carry a latch ter bit, and also simple driving means, which 5'0 side view partly in vertical section,

of a bit head at right angles to the view'in Fig.

1, but in lieu of a core tube containing a center bit locked in drilling position.

Various advantages of this invention may be embodied in a bit head within which a separate the I turonbarrel [or 3 is an annular recess, as the cirelement 5 into engagement with core barrel 2 or center bit I. The wall of center bit 3 or core barrel 2 contains a recess 8 into which latch i may be seated for locking. Member 4 preferably carries latch member 5. Fig. 2 illustrates a pairof opposed latch balls 5, but other members may beusedif desired. Preferably the seat cumferential groove shown, to permit relative rotation of the bit about a core barrel and to facilitate locking the central cylinder without twisting. Outside of cylinder -2 or 3, and preferably in the faces! shell, I, is a complementary recess I, having sloping faces, preferably sloping upwardly to the latch 5 as the carrier or the' groove seat is at the bottom of its ,downward play. Into this recess latch 5 may be withdrawn as the latch is carried down. Latch 5 preferably the thrust of cutters it against the bottom of the bore hole assures positive upward locking move- .ment of latch 5 when the bit head is on bottom' is spherical, at least at its ends. It is housed simply in an opening in the wall of carrier l communicating between the outer shell 5 and inner barrel 2 or 3. Thus ball 5 may be wedged into inner seat 6 by the inner wall of shell i, or displaced into outer recess i when carri'er l moves downwardly. Member d reciprocates or floats within the bit head to lock central cylinder 2 or 3 as it rises, and to unlock as it falls. To limit upward motidn of inner carrier d, the upper walls within shell i are formed to abut the carrier at.

the top of its play. Thus the center bit or the core barrel may be locked at the bottom of the bit head.

In order to keep carrier 8 from falling out of the bit head, a stop element is contained in shell i. As shown, carrier 6 contains a vertical slot 8 of limited extent into which a screw stud 3 may extend from shell 9. Studs may also limit the upward play of carrier 5. Stud 9 is inserted after carrier i is assembled within shell I, and in fact constitutes the only locking element required for the entire bit.

Carrier -6 may function not only to contain and to actuate latch 5, but also to carry and to operate rotatable cutters. A pair of cutters id is shown in the drawing, carried on spindles at the lower end of carrier Q. The weight of these cutters assures a downward unlocking pull on latch 5 when the bit head is-off bottom; while ready to cut. I

In Fig. 2 is illustrated the interlocking contour of inner carrier 4 with the inner recess of shell i. This form comprises a spline connection ii of substantial size, which not only permits inner carrier l to reciprocate vertically but also serves as rugged means to rotate carrier 5 and the cutters carried by it. In lieu of the pair of opposed splines l I shown, other members or arrangements may be selected to attain balance and strength. Extensive faces and pronounced shoulders as shown also contribute strength and lessen whipping or rotational play in the bit head. It' will be observed that the. spline or other contours serve also to align the inner carrier readily with the locking stud 9, and ball 5 with recess l.

' Other detailed elements contribute to the advantages of this invention. In Figs. 1 and 2, core barrel 2 is shown to contain an inner core retaining cylinder l2, which is accommodated preferably within a slight enlargement at the bottom of the core barrel. This is sufllcient in height to permit some vertical play of retainer i2. Within this retainer are prongs i3 to bind a core against slipping downwardly in the retainer. Below retainer l2 and pivoted to the bottom of inner core tube 2 are dogs Id, adapted to be pressed downwardly and into ,a coreby pressure thereagainst by retainer it.

In the modification shown in Fig. 3, center bit 3 utilizes a ratchet ring l5 that iscast or welded within the bottom of inner carrier 3.. As shown, the bottom of carrier 3 preferably extends inwardly somewhat, as a supporting shoulder under ratchet ring I5. This ratchet may be secured within carrier Q as a usual element to facilitate interchangeability from core barrel to center bit,

though, as shown in Fig; l a core barrel simply rests thereon. At a suitable intermediate levei of cutter 3, extend ratchet teeth Hi, complementary to ring l5, for engagement and rotation by carrier t from shell i. Below these ratchet downwardly to drill the central area that would otherwiseform a core. Center cutter 3 may comprise fish tail bits or center cone bits or various forms, which may be screwed into the walls of the cutter body. g

It will be observed that drilling fluid may readily flow to the various cutters, outside thecarrier 4 and through recess l; and through openings ll thatmay be provided at the corners of carrier '6. Also the center of bit cylinder 53 may contain fluid passages. However, a core barrel 2 as shown in Fig. lis provided at the top with the usual valve, and at the bottom rests simply against any substantial inflow of fluid.

Both core barrel 2 and center bit 3 are capped at the top with suitable means, such as knob 88, for engagement by known wire line grap elements.-

In operation,-the bit head may be assembled by inserting inner carrier d and simply fastening with looking stud 9. Whenever desired the center bit may be placed in carrier 3, or any suitable length of core barrel with core con tainer l3. If the bit is at bottom, the core barseat against the core barrel. The drill then may be rotated to cut with both outer cutters it and inner cutters 2B, and a core gradually may rise in the core barrel. Splines ii rotate carrier 3 and ball 5 with outer shell 1|, but the core barrel 2 anda core remain relatively stationary. If the drill stem is raised and lowered in minor degree as frequently occurs in practical drilling latch ball- 5 is merely pulled down into unlocked position, and returned when the cutters are on bottom. The drill may continue operating if desired, while the core barrel may be withdrawn at any time.

is started upwardly. The core 'tube .may be raised either with a wire line grapple, or it may be attached to a float suillciently massive, for instance alog, to float the load to the surface. In somecases the float ay be designed torise only if the drilling. fluid p ps cease their usual downward pressure. It ls evident that either a new core tube may be inserted, or a center bit. A center bit .after latching. is driven from the splined carrier 4 through ratchets l5, Id. In turn it may be withdrawn at any time as described for core tube 2.

Thus an expeditious and certain method and means of latching core tube or center, or of interchange, is provided, without disturbing the normal operation of drilling, and 'despite the depth of the drill hole. A further advantage lies in the control the driller has of varying the length of core tube. 'tage resides in the fact that should the driller become inattentive or sleep for a time and neglect to lower the drill stem, the core tube or the center bit would continue to drop as the inner cutters 21B continue to operate, and as center bit 3 may continue to operate, for .adistance, determined by the play allowed by slot 8 and stud 9. l V

In accordance with the patent statutes, the

This is accomplished by raising the drill slightly and momentarily while the core tube Also an important'advanprinciples of this invention have been described 7 ammo-1 and illustrated by reference to a particular embodiment thereof in the best mode of application now contemplated, but it is evident that other specific arrangements and adaptations of this invention may now be made by those skilled in the art, within the scope of the appended claims What is claimed is:

1. A drill bit comprising an outer shell containing a central recess, a carrier housed therein for vertical play, a central opening through the carrier to receive a core barrel, a latch carried within the shell and operative with vertical movement of the carrier to lock and unlock the core barrel against vertical movement in operating position, the carrier bearing against the latch for actuation thereof. I

2. A drill bit head comprising an outer shell carrying cutters and containing a central recess, a carrier housed therein for vertical play and carrying roller cutters, means within the recess to limit vertical play of the carrier therein, a central opening through the carrier and a cylindrical bit head element housed therein carrying a seat for a latch, a latch supported within the shell and contacting the carrier for actuation by vertical play of the carrier to seat and unseat against the cylindrical element.

3. A drill bit comprising an outer shell carrying cutters and containing a central recess, a carrier housed therein for vertical play and carrying roller-cutters, a central opening through the carrier and a core barrel housed therein and bearing a recess in its side wall to receive a latch element, the carrier containing an inner shoulder to support the core tube and containing an opening in its wall communicating between the core barrel recess and the outer shell, a recess in the shell having walls sloping upwardly to the bottom of the latch opening when the inner carrier is at the top of its play, and a latch in the carrier opening having spherical ends adapted to be forced into the core barrel recess when the carrier is at the top of its play and to be forced into the shell recess when the carrier is at the bottom of itsplay.

4. A drill bit comprising an outer shell carrying cutters and containing a central recess, a carrier housed therein bearing a spline connectlon with the shell to efiect rotation and free for vertical play, roller cutters suspended from the carrier, 9. central opening through the carrier and a tubular element bearing a center cutter housed therein, said element bearing a recess in its side wall to receive a'latch element, the carrier containing an inner shoulder to support the tubular element and containing an opening in its wall communicating between the tubular element latch reces and the outer shell, a recess in the shell having walls sloping to force an object toward the cutter latch recess, and a latch in the carrier having spherical ends adapted to be forced into the cutter latch recess when the carrier moves upwardly relatively to the shell.

5. A drill bit comprising an outer shell containing a central recess, a carrier housed therein for vertical play, a central opening withinthe carrier to receive a cylindrical element, a series of ratchet teeth secured within the carrier opening, and a spherical latch engaged by the walls of the carrier and adapted to be forced by play of the carrier to bear against a cylindrical element within the central opening.

6. A drill bit comprising an outer shell containing a central recess, a carrier housed therein for vertical play, a central opening within the carrier to receive a cylindrical element, a series of ratchet teeth secured within the carrier opening, and a spherical latch engaged by the walls of the carrier and adapted to be forced by play of the carrier to bear against a cylindrical element within the central opening, and. a cylindrical element carrying a center bit fltted within the central opening of the carrier, the walls of the center bit bearing ratchet teeth to engage the ratchet teeth within the carrier.

7. A drill bit comprising an outer shell carrying cutters and containing a central recess, a carrier housed therein, the contacting contours of the recess and of the carrier being interlocking to guide and to rotate the carrier with the shell, the carrier being mounted for limited vertical play, the carrier containing a central opening therethrough to receive a cylindrical element, the walls of a cylindrical element therein containing a cricumferential groove to seat a latch, the carrier wall housing a spherical latch to contact the shell wall and be forced thereby to seat in the circumferential groove, and a recess in the shell positioned and adapted to receive a portion of the latch when the carrier is in relatively lower position.

8. A drill bit comprising an outer shell, a carrier containing a central opening housed in the shell for vertical play, a spherical latch element housed in the carrier, in the shell wall a recess having a sloping face to force the latch to extend into the central opening.

9. A tubular element adapted to be housed in the central opening of a core bit and containing a circumferential groove in the side walls thereof to act as a latch seat.

CHARLES A. DEAN. 

